Beta type aluminas are crystalline materials of the formula Na.sub.2 O--11Al.sub.2 O.sub.3 or Na.sub.2 O--6Al.sub.2 O.sub.3 where the Na may be substituted in whole or in part by other alkali or alkaline earth elements. In the sodium sulfur cell the beta alumina electrode forms a barrier between molten sulfur and molten sodium. The electrode permits the flow through it of sodium ions, whereby Na.sub.2 S is formed, generating power when a load is applied to output electrodes in contact with opposite sides of the cell.
It is desirable that the beta alumina for application on a solid electrolyte be strong and dense. In the past such products have been formed by classical sintering techniques where powder of the desired beta alumina composition is compacted into the desired shape by molding and then fired to produce the final product.
The present invention provides a method by which bodies of superior strength and low porosity can be made.